Page 18 - A Primer of Oilwell Drilling, 7th Edition

afety training is part of everyday life for all hands on a drilling
Srig. There are safety meetings at the beginning of every tour 14
Petroleum Extension-The University of Texas at Austin
and before each new part of a job. Outside training, such as well
control schools and helicopter safety training for offshore crews, is
also required for drilling personnel. The equipment used to drill
a well is technical and complex, and those who run the equipment
must be well trained. Rig Safety and
The international Association of Drilling Contractors (iADC)
keeps a list of detailed statistics on accident rates in the drilling industry. Environmental
The annual statistics can be viewed at iADC’s Web site (www.iadc.
org). One statistic is the total number of any type of accident that Concerns
occurs for every one million man-hours worked. This number has
declined slightly from 2002–2007 at an average of 11.16 accidents
per one million man-hours worked. A normal number of hours one
person might work on a drilling rig is about 3,100 man-hours in one
year. So, a five-person crew will work roughly 15,500 man-hours in
one year. Using the average accident rate shown above, the number
of accidents that might be estimated to occur in one year in the five-
person crew is 0.18 or less than one. This calculation suggests the
average drilling crewmember is a safe worker.
The total number of man-hours actually worked in the worldwide
drilling industry is enormous and increases as more rigs are added
to the world feet. Table 3 shows the annual man-hours worked and
the total accident frequency rate from the iADC data base. Although
safety can always be improved, these statistics suggest the industry
is becoming safer because the accident rate has decreased with the
increasing work time.

Table 3
IADC Annual Work Time and Accident Statistics

year Total Man-Hours accident frequency Total accidents

2007 446,335,455 10.24 4,572

2006 418,954,216 10.85 4,547
2005 369,693,317 11.72 4,332

2004 336,122,663 11.29 3,794

2003 301,959,960 11.16 3,369
2002 281,350,992 11.72 3,297

Source: IADC

189